Viking invasions of Ireland

The Viking invasions of Ireland occurred from 795 to 1014 when the Norse Vikings of Scandinavia and the North Sea islands launched several incursions into Ireland as part of their greater expansion into the British Isles. The first attack came in 795 against the Irish monastery of Raithlin, and, over the next few centuries, the Vikings established settlements along the Irish coast and colonized much of the country. However, the interior areas remained loyal to the Celtic Christian kingdoms, and, after the 1014 Battle of Clontarf, the Viking expansion against the Irish states was brought to an end.

Background
The early Viking raids on Ireland began in the 790s AD. They were comparatively small scale and it was more than 40 years before larger groups came to settle. The first reported Viking attack came in 795 against the monastery of Rechru (Raithlin) which was "laid waste". Raithlin lay off the northeast coast of Ireland, an easy journey for marauders making their way from Scotland, but soon the Vikings swept south, attacking Inis Patraic off the coast of County Dublin in 798 and smashing the much-revered shrine of Do Chonna. Just as they had in England, the Viking raids caused outrage, increased by the fact that monasteries and churches, with their easily portable treasures, were the raiders' principal targets. By 807 Viking raiders reached the west coast of Ireland, burning monasteries as they went. Occasionally the Irish fought back successfully; an annal entry for 811 speaks of a "slaughter of pagans" by the men of Ulster. The Book of Kells was brought to Ireland after a raid on the monastery at Iona in Scotland.

History
The main accounts of the early Viking raids come from chronicles such as the Annals of Ulster, which were compiled in monasteries. The writers reserved particular venom for the Norsemen, referring to them as geinti ("heathens") and holding up the Viking raids as an example of divine wrath against an Ireland that had turned away from God.

Early attacks
The early attackers, who seem to have come from Norway, gradually expanded the field of their operations, in the south reaching Cork by 822 AD, and in the north plundering the monastery of Bangor in 824, where they scattered the relics of Saint Comgall from its shrine in a shocking act of sacrilege. Unlike in France and England, there was no centrally organized resistance to the Vikings in Ireland, which may have encouraged the Scandinavians to mount further raids. In the 830s, these became more serious, sometimes penetrating deep inland; in 837 two large Viking fleets appeared carrying thousands of warriors (probably from the Norse settlements in Scotland), one on the Boyne and another on the Liffey (near the site of present-day Dublin). The army of the Ui Neill kings, which tried to resist them, was cut to pieces.

In 839, a Viking fleet stayed over the winter for the first time in Lough Neagh, and remained for two years. If this was a grim development, far worse was to come. For in 841 the Vikings began to establish fortified naval bases, or longphorts, first at Linn Duachaill in County Louth and at Dublin and then, in the following decade, at a number of other ports including Lough Ree (845) and Cork (848). The main laeder of the Viking leaders in the 840s was Turgeis, who operated from the longphorts at Lough Ree, and whose attacks ranged widely through Connaught and Meath, including the abbey of Clonmacnoise. At the latter, his wife Ota is said to have performed a pagan divinatory rite called seidr, while draped across the high altar. Finally, in 845, Turgeis was captured by Maell Sechnaill, the King of Tara, and drowned in Lough Owel.